With American-backed ground forces poised to recapture Mosul in Iraq and Raqqah in Syria, Islamic State’s de facto capitals, U.S. commanders are confident they soon will vanquish the militant group from its self-declared caliphate after three years of fighting.

But the White House has yet to define strategy for the next step in the struggle to restore stability in the region, including key decisions about safe zones, reconstruction, nascent governance, easing sectarian tensions and commitment of U.S. troops.

Nor has the Trump administration set policy for how it will confront forces from Iran and Russia, the two outside powers that arguably gained the most in the bitter conflict — and that now are hoping to collect the spoils and expand their influence.

Iran, in particular, is pushing to secure a land corridor from its western border across Iraq and Syria and up to Lebanon, where it supports Hezbollah militants, giving it a far larger foothold in the turbulent region.

“Right now everyone is positioned” for routing Islamic State “without having the rules of the road,” said Michael Yaffe, a former State Department envoy for the Middle East who is now vice president of the Middle East and Africa center at the U.S. Institute of Peace. “That’s a dangerous situation.”

The risk of a broader confrontation was clear in recent weeks when a U.S. F/A-18 shot down a Syrian fighter jet for the first time in the multi-sided six-year war, provoking an angry response from Russia, which supports Syrian President Bashar Assad…